Manufacturing method of package-on-package structure

ABSTRACT

A manufacturing method of a package-on package structure including at least the following steps is provided. A die is bonded on a first circuit carrier. A spacer is disposed on the die. The spacer and the first circuit carrier are connected through a plurality of conductive wires. An encapsulant is formed to encapsulate the die, the spacer and the conductive wires. A thickness of the encapsulant is reduced until at least a portion of each of the conductive wires is removed to form a first package structure. A second package structure is stacked on the first package structure. The second package structure is electrically connected to the conductive wires.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of U.S. provisional application Ser. No. 62/410,851, filed on Oct. 21, 2016. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of the specification.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention generally relates to a manufacturing method of a package structure, and more particularly relates to a manufacturing method of a package-on-package (POP) structure.

2. Description of Related Art

In order for electronic product design to achieve being light, slim, short, and small, semiconductor packaging technology has kept progressing, in attempt to develop products that are smaller in volume, lighter in weight, higher in integration, and more competitive in the market. For example, 3D stacking technologies such as POP have been developed to meet the requirements of higher packaging densities. As such, how to achieve a thinner POP structure with lower manufacturing cost has become a challenge to researchers in the field.

SUMMARY OF THE INVENTION

The disclosure provides a manufacturing method of a package-on-package (POP) structure, which reduces the overall thickness and the manufacturing cost thereof.

The disclosure provides a manufacturing method of a POP structure. The method includes at least the following steps. A die is bonded on a first circuit carrier. A spacer is disposed on the die. The spacer and the first circuit carrier are connected through a plurality of conductive wires. An encapsulant is formed to encapsulate the die, the spacer and the conductive wires. A thickness of the encapsulant is reduced until at least a portion of each of the conductive wires is removed to form a first package structure. A second package structure is stacked on the first package structure. The second package structure is electrically connected to the conductive wires.

Based on the above, the spacer disposed on the die is conducive to form the conductive wires. In addition, since the thickness of the encapsulant is reduced and also at least a portion of each of the conductive wires is removed to form a first package structure, the rest portion of the conductive wires in the encapsulant may serve as the electrical connecting path between the first package structure and the second package structure. In other word, it is unnecessary to dispose additional interposer between the first package structure and the second package structure for electrical connection. Hence, the overall thickness of the POP structure may be reduced and the lower manufacturing costs may be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

FIG. 1A to FIG. 1F are schematic cross-sectional views illustrating manufacturing method of a POP structure according to an embodiment of the disclosure.

FIG. 2A to FIG. 2F are schematic cross-sectional views illustrating manufacturing method of a POP structure according to another embodiment of the disclosure.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferred embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

FIG. 1A to FIG. 1F are schematic cross-sectional views illustrating manufacturing method of a POP structure according to an embodiment of the disclosure. Referring to FIG. 1A, a first circuit carrier 110 is provided. The first circuit carrier 110 may have a top surface S1 and a bottom surface S2 opposite to the top surface S1. For example, the first circuit carrier 110 may include a core layer 112, a top circuit layer 114 disposed on the top surface S1 and the bottom circuit layer 116 disposed on the bottom surface S2 of the first circuit carrier 110. The core layer 112 is disposed between and electrically connects the top circuit layer 114 and the bottom circuit layer 116. In some embodiments, the top circuit layer 114 and the bottom circuit layer 116 may respectively include a plurality of conductive pads 114 a and 116 a used for further electrical connection. Moreover, the conductive pads 114 a and the conductive pads 116 a may be formed by the same material and the same process such as using copper, solder, gold, nickel, or the like through photolithography and etching processes. In some other embodiments, the conductive pads 114 a and the conductive pads 116 a may be formed by different materials and/or different processes according to the design requirement.

The core layer 112 may further include embedded circuit layers serving as an intermediate circuit layer electrically connected to the top circuit layer 114 and the bottom circuit layer 116. The core layer 112 may include a base layer and a plurality of conductive vias penetrating through the base layer. The two opposite ends of the conductive vias of the core layer 112 may electrically connect to the conductive pads 114 a of the top circuit layer 114 and the conductive pads 116 a of the bottom circuit layer 116. In some embodiments, the first package structure 100 may include a plurality of conductive structures 118 formed on the bottom surface S2 of the first package structure 100. For example, a material of the conductive structures 118 may include copper, tin, gold, nickel or other suitable conductive material. The conductive structures 118 may be, for example, conductive bumps, conductive pillars, or solder balls formed by a ball placement process and a reflow process. It should be noted that other possible forms and shapes of the conductive structures 118 may be utilized for further electrical connection. In some embodiments, the conductive structures 118 may form an array arranged to have fine pitch on the bottom surface S2 of the first circuit carrier 110 for requirement in the subsequent processes.

A first die 120 may be disposed on the top surface S1 of the first circuit carrier 110. The first die 120 may be electrically connected to the first circuit carrier 110 through flip-chip bonding. In some embodiment, an active surface (not illustrated) of the first die 120 is coupled to the conductive pads 114 a of the top circuit layer 114 of the first circuit carrier 110 through a plurality of conductive bumps 122. The conductive bumps 122 may be copper bumps. In some embodiments, solders (not illustrated) may be applied onto surfaces of the conductive bumps 122 to couple with the conductive pads 114 a. The first die 120 may be, for example, an ASIC (Application-Specific Integrated Circuit). In some embodiments, the first die 120 may be used to perform logic applications. However, it construes no limitation in the disclosure. Other suitable active devices may also be utilized as the first die 120.

Referring to FIG. 1B, a spacer 130 is disposed on the first die 120. In addition, the spacer 130 is bonded to the first die 120 through an adhesive layer 140. In some embodiments, the adhesive layer 140 may be a die attach film or forming from the adhesive composition including an epoxy resin. The adhesive layer 140 may be formed by methods such as spin coating, inject printing or other suitable methods for providing a structural support without the need for mechanical clamping between the first die 120 and the spacer 130.

The spacer 130 may include a second circuit carrier 132 with conductive pads on the surface opposite to the first die 120 for the subsequent bonding process. It should be noted that other suitable forms of the spacer 130 may be utilized and the details will be described later in other embodiments. In some embodiments, the spacer 130 may serve as a dummy chip for performing the subsequent wire bonding process and/or providing a spacer function to prevent damage to the first die 120. The size and the thickness of the spacer 130 may construe no limitation to the unit sizes and unit thicknesses of the first die 120. In some embodiment, the spacer 130 may be a semiconductor carrier having a similar shape or appearance as that of a chip while not having active devices formed therein. In some other embodiments, the spacer 130 and the first die 120 may be mechanically coupled but electrically isolated from each other when the entire manufacturing process is completed.

Referring to FIG. 1C, the spacer 130 and the first circuit carrier 110 are connected through a plurality of conductive wires 150. For example, the conductive wires 150 may be formed through a wire bonder (not illustrated). The types of the wire bonder may include wedge bond or ball bond or other suitable wire bonder according to the design requirement. Moreover, the conductive wires 150 are connected between the second circuit carrier 132 of the spacer 130 and the first circuit carrier 110. A material of the conductive wires 150 may be gold, copper or other suitable material, which is not limited thereto. In some embodiments, each of the conductive wires 150 may include a first welding segment 152, a sacrificial segment 154 and a second welding segment 156. Each of the first welding segments 152 of the conductive wires 150 is coupled to the first circuit carrier 110 and each of the second welding segments 156 of the conductive wires 150 is coupled to the second circuit carrier 132 of the spacer 130. The conductive wires 150 are formed from the first circuit carrier 110 to the spacer 130. Moreover, each of the sacrificial segments 154 of the conductive wires 150 is formed between one of the first welding segments 152 and one of the second welding segments 156. In other word, each of the conductive wires 150 may be formed in the sequence of the first welding segment 152, the sacrificial segment 154 and the second welding segment 156.

In some embodiments, the wire bonder may include an automated device that welds the conductive wires 150. For instance, each of the conductive wires 150 is fed through a bonding tool such as a capillary (not illustrated) that applies heat, ultrasonic energy, pressure, or the combination thereof to bond each of the conductive wires 150 between the first circuit carrier 110 and the spacer 130. In some embodiments, each of the first welding segments 152 of the conductive wires 150 may include a welding portion 152 a bonded to the first circuit carrier 110 and a wire portion 152 b coupled to the welding portion 152 a. For example, the welding portion 152 a of each of the first welding segments 152 may be formed through ball bond, wedge bond, or other suitable bond depending on the design requirement. After bonding the welding portion 152 a to the top surface S1 of the first circuit carrier 110, the wire portion 152 b of each of the first welding segments 152 coupled to the welding portion 152 a may be delivered out by the bonding tool of the wire bonder. For instance, the bonding tool of the wire bonder may move upwards from the first circuit carrier 110 to form the wire portion 152 b in a vertical manner.

Next, the bonding tool may move in a direction upward away from the first circuit carrier 110 and towards the spacer 130 to form the sacrificial segment 154. An arcing shape in the sacrificial segment 154 of each of the conductive wires 150 may be formed. In addition, a loop height H1 of each of the conductive wires 150 may be a distance between the peak of the arcing shape of the sacrificial segment 154 and the bottom end of the welding portion 152 a of the first welding segment 152 coupled to the first circuit carrier 110. The loop height H1 may depend on the type of the wire bonder and/or the design requirement, which is not limited thereto. Subsequently, the bonding tool of the wire bonder may be positioned at the conductive pads of the second circuit carrier 132 of the spacer 130 and a tail bond of each of the second welding segment 156 of the conductive wires 150 may be formed to bond the second circuit carrier 132. As such, the wire bonding process on, the first circuit carrier 110 and the second circuit carrier 132 of the spacer 130 is completed.

In some embodiments, an angle θ1 between the first welding segment 152 of each of the conductive wires 150 and the first circuit carrier 110 is greater than or equal to an angle θ2 between the second welding segment 156 of each of the conductive wires 150 and the spacer 130. The angle θ1 may depend on the types of the wire bonding and/or the design requirement. For example, a ball bonder welds a conductive ball on the conductive pads 114 a of the first circuit carrier 110 to a contact with each of the conductive wire 150 extending away from the conductive ball at right angle. However, for the wedge bonder, in some embodiments, it presses the side of the conductive wires 150 against the contact so the angle θ1 between each of the first welding segments 152 of the conductive wires 150 and the top surface S1 of the first circuit carrier 110 may be less than 90 degree, but substantially close to 90 degree. In some other embodiments, each of the second welding segments 156 of the conductive wires 150 may be perpendicular to the spacer 130. As such, the angle θ2 may be 90 degree or substantially close to 90 degree.

Referring to FIG. 1D, an encapsulant 160 is formed on the top surface S1 of the first circuit carrier 110 to encapsulate the first die 120, the spacer 130, the adhesive layer 140, and the conductive wires 150. In some embodiments, a thickness T1 of the encapsulant 160 is greater than the loop height H1 of each of the conductive wires 150. The encapsulant 160 may include a molding compound formed by a molding process. In some embodiments, the encapsulant 160 may be formed by an insulating material such as epoxy or other suitable resins. However, it construes no limitation in the disclosure.

Referring to FIG. 1E, the thickness T1 of the encapsulant 160 is reduced until at least a portion of each of the conductive wires 150 are removed to form a first package structure 100. For instance, the thickness T1 of the encapsulant 160 is reduced to a thickness T2 as shown in FIG. 1E. When the thickness T1 of the encapsulant 160 is reduced, the sacrificial segments 154 of the conductive wires 150 may be removed. In addition, a portion of each of the first welding segments 152 of the conductive wires 150 and a portion of each of the second welding segments 156 of the conductive wires 150 may be exposed through the encapsulant 160. In other word, since the sacrificial segments 154 of the conductive wires 150 are removed while the portion of the first welding segments 152 and the portion of the second welding segments 156 remain in the encapsulant 160, the conductive wires 150 is no longer a continuous wires. Under this condition, the spacer 130 is no longer coupled to the first circuit carrier 110 though the conductive wires 150. As such, the spacer 130 is no longer electrically connected to the first circuit carrier 110. In other word, the spacer 130 serves as a dummy spacer after reducing the thickness T1 of the encapsulant 160.

In some embodiments, the encapsulant 160 may be removed by a grinding process. Moreover, the grinding process may be mechanical grinding, chemical mechanical polishing (CMP), etching, or other suitable method, which is not limited thereto. Moreover, after reducing the thickness T1 of the encapsulant 160, a top surface of the wire portion 152 b of each of the first welding segment 152 and a top surface of each of the second welding portion 156 are exposed from the encapsulant 160. In some embodiments, after reducing the thickness T1 of the encapsulant 160, the top surface of the wire portion 152 b of each of the first welding segment 152, the top surface of each of the second welding portion 156, and a top surface of the encapsulant 160 may be coplanar. Wherein, the top surface of the encapsulant 160 may be the surface farthest from the first circuit carrier 110. In other word, after reducing the thickness T1 of the encapsulant 160, a height H2 of each of the first welding segments 152 is equal to the thickness T2 of the encapsulant 160.

In one embodiment, after reducing the thickness T1 of the encapsulant 160, the top surface of the wire portion 152 b may be used for further electrical connection with the first circuit carrier 110. The top surface of each of the second welding portion 156 may be dummy paths. In some other embodiments, after reducing the thickness T1 of the encapsulant 160, both of the top surface of the wire portion 152 b of each of the first welding segment 152 and the top surface of each of the second welding portion 156 may serve as the conductive path for further electrical connection according to the design requirement. In addition, it should be noted that the thickness reducing process as shown in FIG. 1E is able to aid the overall thickness reduction in the package structure as a whole, thereby achieving package miniaturization.

Referring to FIG. 1F, a second package structure 200 is stacked on the first package structure 100 to form a package-on-package (POP) structure 10. For example, the second package structure 200 is electrically connected to the conductive wires 150 of the first package structure 100. In some embodiments, the second package structure 200 may include a second die 202 such as DRAM or NAND flash memory. In some other embodiments, other active devices may also be utilized in the second package structure 200. In some embodiments, the second package structure 200 may include a plurality of conductive terminals 204 as the electrical connection path between the second package structure 200 and the first package structure 100. Moreover, in some embodiments, the second die 202 and the conductive terminals 204 may be electrically connected through circuit layers similar to the connection between the first die 120 and the conductive structures 118.

In one embodiment, the second package structure 200 may include a central region CR and a peripheral region PR surrounding the central region CR. For instance, the second die 202 may be located in the central region CR and the conductive terminals 204 may be disposed in the peripheral region PR. Moreover, when the second package structure 200 is stacked on the first package structure 100, the second die 202 in the central region CR of the second package structure 200 may be disposed corresponding to the first die 120 of the first package structure 100. In addition, each of the conductive terminals 204 in the peripheral region PR of the second package structure 200 may be disposed on one of the first welding segments 152 of the conductive wires 150 exposed by the encapsulant 160 of the first package structure 100, respectively. In one embodiment, the second die 202 in the central region CR of the second package structure 200 may be staggered from the first die 120 of the first package structure 100. In another embodiment, the conductive terminals 204 may be disposed in both of the central region CR and the peripheral region PR for electrical connection to the first package structure 100. In some embodiments, a thermal conductive layer (not illustrated) may be disposed in thermal contact or thermally coupled between the second package structure 200 and the first package structure 100 for enhancing the heat dissipation efficiency. As such, the stress applied onto the POP structure 10 during the subsequent reliability tests may be shared by the thermal conductive layer for increasing the reliability of the POP structure 10.

Since the first welding segments 152 may serve as the electrical connection path between the first package structure 100 and the second package structure 200, an additional interposer for electrically connecting between the first package structure 100 and the second package structure 200 can be omitted. Thereby the overall thickness of the POP structure 10 and the manufacturing costs may be reduced.

FIG. 2A to FIG. 2F are schematic cross-sectional views illustrating manufacturing method of a POP structure according to another embodiment of the disclosure. Referring to FIG. 2A, the first circuit carrier 110 is provided and the first die 120 is bonded on the first circuit carrier 110. It should be noted that the embodiment of FIG. 2A is similar to the embodiment of FIG. 1A, so the detailed descriptions are omitted herein.

Referring to FIG. 2B, a spacer 330 is disposed on the first circuit carrier 110 and bonded to the first die 120. For example, the spacer 330 includes a conductive plate 332 serving as a heat-dissipating metal plate. In addition, the conductive plate 332 of the spacer 330 may be suitable for performing the subsequent wire bonding process. A material of the conductive plate 332 may include a thermally and electrically conductive material such as aluminum, copper or alloys thereof. However, a material of the conductive plate 332 depends on the design requirement construing no limitation the disclosure.

Moreover, a thermal adhesive layer 340 may be disposed between the first die 120 and the spacer 330. In some embodiments, the thermal adhesive layer 340 may include die attach compositions possessing a high thermal conductivity such as silver, silver coated or aluminium nitride particles formed by such as spin coating, inject printing or other suitable methods. However, a material and forming processes of the thermal adhesive layer 340 construe no limitation in the disclosure. The thermal adhesive layer 340 may serve as a direct thermal conductivity path from the first die 120 to the spacer 330 and further enhance the heat dissipation efficiency during the heat generated from the first die 120. Furthermore, the thermal adhesive layer 340 may provide a structural support without the need for mechanical clamping between the first die 120 and the spacer 330.

Referring to FIG. 2C, the spacer 330 and the first circuit carrier 110 are connected through a plurality of conductive wires 350. It should be noted that a material and forming methods of the conductive wires 350 may be similar to the material and the forming methods of the conductive wires 150 shown in FIG. 1C. The detailed descriptions are omitted herein. In the present embodiment, the conductive wires 350 may be connected between the conductive plate 332 of the spacer 330 and the first circuit carrier 110. In addition, each of the conductive wires 350 may include a welding segment 352 connected to the first circuit carrier 110 and a sacrificial segment 354 connected between the welding segment 352 and the spacer 330. In other word, the conductive wires 350 are connected from the first circuit carrier 110 through the welding segment 352 to the spacer 330 through the sacrificial segment 354.

In addition, each of the welding segments 352 of the conductive wires 350 may include a welding portion 352 a coupled to the first circuit carrier 110 and a wire portion 352 b connected to the welding portion 352 a. For example, the welding portion 352 a of each of the welding segments 352 may be formed through ball bond, wedge bond or other suitable bond depending on the design requirement. It should be noted that the forming process of the welding portions 352 a and the wire portions 352 b of the welding segments 352 may be similar to the forming process of the welding portions 152 a and the wire portions 152 b of the first welding segments 152 illustrated in FIG. 1C. The detailed descriptions are omitted herein.

Each of the sacrificial segments 354 of the conductive wires 350 may include an arc-shape portion 354 a and a tail portion 354 b. The forming process of the sacrificial segments 354 may be similar to the forming process of the sacrificial segments 154 and the second welding segments 156 of the conductive wires 150. The detailed descriptions are omitted herein. In addition, a loop height H3 of each of the conductive wires 350 may be a distance between the peak of the arc-shape portion 354 a of the sacrificial segment 354 and the bottom end of the welding portion 352 a of the first welding segment 352 coupled to the first circuit carrier 110. It should be noted that the loop height H3 depends on the types of the wire bonder and/or the design requirement, which is not limited thereto.

In some embodiments, an angle θ3 between the welding segment 352 of each of the conductive wires 350 and the first circuit carrier 110 is greater than an angle θ4 between the sacrificial segment 354 of each of conductive wires 350 and the spacer 330. Similar to the embodiment illustrated in FIG. 1C, in the present embodiment, the angle θ3 (similar to the angle θ1) and the angle θ4 (similar to the angle θ2) may depend on the types of the wire bonding and/or the design requirement.

Referring to FIG. 2D, the encapsulant 160 is formed on the first circuit carrier 110 to encapsulate the first die 120, the spacer 330, the adhesive layer 340 and the conductive wires 350. It should be noted that the process of the embodiment illustrated in FIG. 2D is similar to the process of the embodiment of illustrated in FIG. 1D, so the detailed descriptions are omitted herein. Referring to FIG. 2E, the thickness T1 of the encapsulant 160 is reduced until at least a portion of each of the conductive wires 350 are removed to form a first package structure 300. The reducing methods of the embodiment illustrated in FIG. 2E is similar to the reducing methods of the embodiment of illustrated in FIG. 1E, so the detailed descriptions are omitted herein.

In the present embodiment, the sacrificial segments 354 of the conductive wires 350 are removed. For instance, the thickness T1 of the encapsulant 160 is reduced to a thickness T3 as shown in FIG. 2E. In addition, after reducing the thickness T1 of the encapsulant 160, a top surface 332 a of the conductive plate 332 of the spacer 330 is exposed from the encapsulant 160. Moreover, a top surface of the wire portion 352 b of each of the welding segments 352 of the conductive wires 350 are exposed through the encapsulant 160. In other word, the sacrificial segments 354 of the conductive wires 350 are removed while a portion of the welding segments 352 remain in the encapsulant 160. Under this condition, the spacer 330 is not connected to the conductive wires 350 and also no longer electrically connected to the first circuit carrier 110 though the conductive wires 350. As such, the spacer 330 is no longer electrically connected to the first circuit carrier 110. In some embodiments, after reducing the thickness T1 of the encapsulant 160, the top surface of the wire portion 352 b of each of the welding segment 352, the top surface 332 a of the conductive plate 332 of the spacer 330 and a top surface of the encapsulant 160 are coplanar. Wherein, the top surface of the encapsulant 160 may be the surface farthest from the first circuit carrier 110. In other word, after reducing the thickness T1 of the encapsulant 160, a height H4 of each of the welding segments 352 is equal to the thickness T3 of the encapsulant 160. In addition, it should be noted that the thickness reducing process as shown in FIG. 2E is able to aid the overall thickness reduction in the package structure as a whole, thereby achieving package miniaturization. Moreover, the spacer 330 including the conductive plate 332 may first serve as the conductive bonding pad for forming the conductive wires 350 as shown in FIG. 2D. Subsequently, since the sacrificial segments 354 of the conductive wires 350 are removed after reducing the thickness T1 of the encapsulant 160, the spacer 330 is electrically floated. Therefore, the spacer 330 including the conductive plate 332 may be used as the heat-dissipating element in the first package structure 300.

Referring to FIG. 2F, the second package structure 200 is stacked on the first package structure 300 to form a POP structure 20. For example, the second package structure 200 is electrically connected to the conductive wires 350 of the first package structure 100. In some embodiments, when the second package structure 200 is stacked on the first package structure 300, the second die 202 in the central region CR of the second package structure 200 may be disposed corresponding to the first die 120 of the first package structure 300. In addition, each of the conductive terminals 204 in the peripheral region PR of the second package structure 200 may be disposed on one of the welding segments 352 of the conductive wires 350 exposed by the encapsulant 160 of the first package structure 300. In one embodiment, the second die 202 in the central region CR of the second package structure 200 may be staggered from the first die 120 of the first package structure 300. In another embodiment, the conductive terminals 204 may be disposed in both of the central region CR and the peripheral region PR of the second package structure 200 for electrical connection to the first package structure 300.

Based on the above, the spacer disposed on the die is conducive to the forming process of the conductive wires. Moreover, since at least a portion of the conductive wires are removed during reducing the thickness of the encapsulant, the rest portion of the conductive wires remaining in the encapsulant may be used as the electrical connecting path between the first package structure and the second package structure. As a result, it is unnecessary to dispose additional interposer between the first package structure and the second package structure for electrical connection. Therefore, not only the overall thickness of the POP structure but the manufacturing cost may be reduced. In addition, the spacer may be exposed from the encapsulant so the spacer may serve as a heat-dissipating element after reducing the thickness of the encapsulant. As such, it may open the possibility to various POP structure designs.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents. 

What is claimed is:
 1. A manufacturing method of a package-on-package (POP) structure, comprising: bonding a die on a first circuit carrier; disposing a spacer on the die; connecting the spacer and the first circuit carrier through a plurality of conductive wires; forming an encapsulant to encapsulate the die, the spacer and the conductive wires; reducing a thickness of the encapsulant until at least a portion of each of the conductive wires are removed to form a first package structure; and stacking a second package structure on the first package structure, wherein the second package structure is electrically connected to the conductive wires.
 2. The manufacturing method of a POP structure according to claim 1, wherein the die is electrically connected to the first circuit carrier through flip-chip bonding.
 3. The manufacturing method of a POP structure according to claim 1, wherein the spacer is bonded to the die through an adhesive layer.
 4. The manufacturing method of a POP structure according to claim 1, wherein the conductive wires are formed through a wire bonder.
 5. The manufacturing method of a POP structure according to claim 1, wherein the spacer comprises a second circuit carrier, the conductive wires are connected between the second circuit carrier and the first circuit canier before reducing the thickness of the encapsulant.
 6. The manufacturing method of a POP structure according to claim 5, wherein each of the conductive wires comprises a first welding segment connected to the first circuit carrier and a second welding segment connected to the spacer before reducing the thickness of the encapsulant, the conductive wires are connected from the first circuit carrier through the first welding segments to the spacer through the second welding segments.
 7. The manufacturing method of a POP structure according to claim 6, wherein an angle between the first welding segment of each of the conductive wires and the first circuit carrier is greater than an angle between the second welding segment of each of the conductive wires and the spacer before reducing the thickness of the encapsulant.
 8. The manufacturing method of a POP structure according to claim 6, wherein each of the conductive wires further comprises a sacrificial segment connecting between the first welding segment and the second welding segment before reducing the thickness of the encapsulant, when reducing the thickness of the encapsulant, the sacrificial segments of the conductive wires are removed.
 9. The manufacturing method of a POP structure according to claim 8, wherein after reducing the thickness of the encapsulant, a portion of each of the first welding segments of the conductive wires and a portion of each of the second welding segments of the conductive wires are exposed by the encapsulant.
 10. The manufacturing method of a POP structure according to claim 8, wherein after the sacrificial segments of the conductive wires are removed, the spacer is electrically floated.
 11. The manufacturing method of a POP structure according to claim 8, wherein the second package structure comprises a plurality of conductive terminals, each of the conductive terminals of the second package structure is disposed on one of the first welding segments of the conductive wires exposed by the encapsulant respectively.
 12. The manufacturing method of a POP structure according to claim 1, wherein the spacer comprises a conductive plate.
 13. The manufacturing method of a POP structure according to claim 12, wherein the spacer is bonded to the die through a thermal adhesive layer.
 14. The manufacturing method of a POP structure according to claim 12, wherein after reducing the thickness of the encapsulant, a surface of the spacer is exposed from the encapsulant.
 15. The manufacturing method of a POP structure according to claim 12, wherein each of the conductive wires comprises a welding segment connected to the first circuit carrier and a sacrificial segment connected between the welding segment and the spacer before reducing the thickness of the encapsulant, the conductive wires are connected from the first circuit carrier through the welding segment to the spacer through the sacrificial segment.
 16. The manufacturing method of a POP structure according to claim 15, wherein an angle between the welding segment of each of the conductive wires and the first circuit carrier is greater than an angle between the sacrificial segment of each of the conductive wires and the spacer before reducing the thickness of the encapsulant.
 17. The manufacturing method of a POP structure according to claim 15, wherein when reducing the thickness of the encapsulant, the sacrificial segments of the conductive wires are removed.
 18. The manufacturing method of a POP structure according to claim 15, wherein after reducing the thickness of the encapsulant, a portion of each of the welding segments of the conductive wires are exposed by the encapsulant.
 19. The manufacturing method of a POP structure according to claim 15, wherein after the sacrificial segments of the conductive wires are removed, the spacer is electrically floated.
 20. The manufacturing method of a POP structure according to claim 15, wherein the second package structure comprises a plurality of conductive terminals, each of the conductive terminals of the second package structure is disposed on one of the welding segments exposed by the encapsulant respectively. 